Definition and experimental validation of a new model for the fatigue of elastomers incorporating deviations from Miners linear law of cumulative damage
Definition and experimental validation of a new model for the fatigue of elastomers incorporating deviations from Miners linear law of cumulative damage
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DOI：
10.1016/j.proeng.2010.03.177
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发表时间：
2010-04
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影响因子：
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通讯作者：
A. Jardin;J. Leblond;D. Berghezan;M. Portigliatti
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文献类型：
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作者：
A. Jardin;J. Leblond;D. Berghezan;M. Portigliatti
对于金属的疲劳，已经多次观察到与Miner线性累积损伤定律的偏差，并建立了模型，但对于弹性体几乎没有进行过类似的研究。本文的第一个目的是提出一个简单的现象学模型，适用于任何类型的材料，并能够定量地再现这种偏差。该模型以连续介质损伤力学为基础，通过适当的演化规律将材料的疲劳损伤与循环次数联系起来，其中损伤的导数表示为瞬时循环载荷和损伤本身的不可分解函数。第二个目的是报告在两种不同弹性材料制成的空竹试件上进行的疲劳实验，并承受两种不同的连续循环载荷。这些实验清楚地证明了对Miner规则的偏离：根据加载顺序和材料类型的不同，Miner的“总累积损害”可能比1低，也可能比1大或小。通常情况下，对Miner规则的偏离在加载顺序颠倒时系统地改变符号。该模型能够较好地再现实验结果，特别是符号的系统变化。
Deviations from Miner’s linear law of cumulative damage have been observed and modeled many times for the fatigue of metals, but almost no analogous studies have been performed for elastomers. The first aim of this paper is to present a simple phenomenological model, applicable to any type of material and able to quantitatively reproduce such deviations. This model is based on continuum damage mechanics and relates the fatigue damage of the material to the number of cycles through some suitable evolution law, in which the derivative of damage is expressed as a non-factorizable function of the instantaneous cyclic load and the damage itself. The second aim is to report fatigue experiments performed on “diabolo” specimens made of two different elastomeric materials, and subjected to two different successive cyclic loadings. These experiments clearly evidence deviations from Miner’s rule: Miner’s “total cumulated damage” may be lower or larger than unity by a small or large amount, depending on the sequence of loadings and the type of material. As a rule, the deviation from Miner’s rule systematically changes sign upon reversal of the sequence of loadings. The model allows for an acceptable reproduction of the experimental results, and especially of this systematic change of sign.